Positive bias in mycophenolic acid concentrations determined by the CEDIA assay compared to HPLC-UV method: is CEDIA assay suitable for therapeutic drug monitoring of mycophenolic acid?

Amitava Dasgupta, Myrtle Johnson

Journal of clinical laboratory analysis 2013 Jan

filter terms:

Both immunoassays and chromatographic methods are available for therapeutic drug monitoring of mycophenolic acid (MPA), an immunosuppressant. We studied the suitability of cloned enzyme donor immunoassay (CEDIA) assay for routine monitoring of MPA by comparing values obtained by the CEDIA assay with corresponding values obtained by using a high-performance liquid chromatography combined with ultraviolet detection (HPLC-UV) method. We compared MPA concentrations obtained by a reference HPLC-UV method and CEDIA assay on Hitachi 917 analyzer (Roche Diagnostics, Indianapolis, IN) using 60 patient specimens (18 liver transplant recipient and 42 kidney transplant recipients). When MPA concentrations in all 60 transplant recipients obtained by the HPLC-UV (x-axis) method were compared with corresponding values obtained by the CEDIA method (y-axis), the following regression equation was obtained: y = 1.1558x + 0.2876 (r = 0.97). Interestingly, much lower bias was observed in 42 renal transplant recipients as revealed by the following regression equation; y = 1.1181x + 0.2745 (r = 0.98). However, more significant positive bias was observed in 18 liver transplant recipients as following regression equation as observed: y = 1.3337x + 0.1493 (r = 0.94). We conclude that MPA concentrations determined by the CEDIA assay showed significant positive bias compared to HPLC-UV method. Therefore, caution must be exercised in interpreting therapeutic drug monitoring result of MPA if CEDIA assay is used. © 2012 Wiley Periodicals, Inc.

Citation

Amitava Dasgupta, Myrtle Johnson. Positive bias in mycophenolic acid concentrations determined by the CEDIA assay compared to HPLC-UV method: is CEDIA assay suitable for therapeutic drug monitoring of mycophenolic acid? Journal of clinical laboratory analysis. 2013 Jan;27(1):77-80